Right. So I have lurked this site for long enough without contributing I think! (10 years, whew.)
Without more preamble; Here is Matilda White.
Reference/Design Sheet: http://imgur.com/enBeTzR
Intro Comic: http://imgur.com/a/ISKP3
Matilda White is a medic in the 109'th Thumaturgic Corps, A military unit that uses magic. She comes from a reality where humanity discovered and utilized magic on a industrial scale, creating a sort of Utopia while always on the hunt for more magic. However, they also found god, literally. While fighting GOD, her magic engine accidentally sent her hurtling across realities to Void City.
How she works, kinda.
Matildas Miracle Engine does not shield her from others magic or absorb it. It merely passively charges itself with the latent energy of the world around her. In a place like Void, it is basically working overtime. As she is a medic, her specialty lies in healing miracles, such as mending flesh and bone without pain, turning sick flesh healthy. She knows how to do the basic offensive spells, like lightning from her finger or a stream of fire.
Theoretically, the Engine could grant her any wish, if she can properly charge it and envision what she wants. But to do anything beyond her training demands massive resources and a very sharp and focused mind. Neither which she posses.